With a total payload mass of 955 kg and target orbit of 505 km SSO, I'm not sure why they went for an XL configuration with those strapons. It appears well within the ability of CA variant, unless a customized payload adapter has added extra mass.

India's Polar Satellite Launch Vehicle, in its 40th flight (PSLV-C38), will launch the 712 kg Cartosat-2 series satellite for earth observation and 30 co-passenger satellites together weighing about 243 kg at lift-off into a 505 km polar Sun Synchronous Orbit (SSO). PSLV-C38 will be launched from the First Launch Pad (FLP) of Satish Dhawan Space Centre (SDSC) SHAR, Sriharikota. This will be the seventeenth flight of PSLV in 'XL' configuration (with the use of solid strap-on motors).

The co-passenger satellites comprise 29 Nano satellites from 14 countries namely, Austria, Belgium, Chile, Czech Republic, Finland, France, Germany, Italy, Japan, Latvia, Lithuania, Slovakia, United Kingdom, and United States of America as well as one Nano satellite from India. The total weight of all these satellites carried on-board PSLV-C38 is about 955 kg.

PSLV-C38 to lower its altitude after separation of Cartosat-2E to inject other satellitesPSLV-C38 upper stage to maneuver to a lower altitude after separation of satellites presumably as a test for a future mission

Director, Vikram Sarabhai Space Centre, Dr Sivan said the plan was to lower the altitude of the rocket in space from 500 km to 350 km to launch the satellites in different orbits. The fourth stage will be kept active till it makes 10 orbits around the earth. Earlier, the fourth stage of the rocket that had launched 20 satellites in one go on June 22, 2016, was cut off for 16 minutes and 30 seconds after the lift-off. The 20 satellites were injected into the same orbit.

Before that, scientists had re-started the fourth-stage engine of the PSLV for four seconds after the rocket injected six Singapore satellites into the same orbit on December 16, 2015. These experiments came in handy for Isro to place eight satellites in different orbits from the fourth stage of the PSLV-C35 on September 26, 2016.

Director, Vikram Sarabhai Space Centre, Dr Sivan said the plan was to lower the altitude of the rocket in space from 500 km to 350 km to launch the satellites in different orbits. The fourth stage will be kept active till it makes 10 orbits around the earth. Earlier, the fourth stage of the rocket that had launched 20 satellites in one go on June 22, 2016, was cut off for 16 minutes and 30 seconds after the lift-off. The 20 satellites were injected into the same orbit.

I guess I sort of misunderstood the report. The brochure indeed says the last customer satellite separates at ~510 km altitude. This maneuver post-separation of satellites is apparently meant as a test for a future mission involving a satellite that requires such a low orbit.

Horray for the first Finnish satellite. Getting the ride to orbit after the second Finnish satellite already got deployed *and* stopped working (Aalto 2 got to ISS on the Cygnus, was deployed and few weeks later ended up no longer responding to commands)

Was originally booked on Falcon 9 along with Formosat, but moved to this rocket after SpaceX delays due to certain unfortunate event that kinda wrecked the schedule last autumn.